Bidirectionally operable torque actuated expandable core chuck

ABSTRACT

A plurality of elongate chucking members equiangularly disposed about a rotatable central camshaft provide a bidirectionally operable cylindrical core chuck which can be expanded radially by simultaneous outward movement of such members relative to the rotational axis of the camshaft. Each of the chucking members includes two spaced coaxial mounting yokes supported by corresponding circular cams located along the camshaft and offset from the rotational axis thereof. A positioning ring concentric with the chuck axis is provided with radial guide pins which maintain the chucking members in equiangular relation to each other as they are moved outwardly in unison as a result of torque development between the camshaft and any one of the chucking members.

United States Patent [72] inventors George E. Reeder, Jr.

Newark, DeL; Soma M. Rohosy, West Chester, Pa. [21] Appl. No. 875,984 [22] Filed Nov. 12, 1969 [45] Patented Nov. 30, 1971 [73] Assignee Beloit Corporation Beloit, Wis.

[54] BIDIRECTIONALLY OPERABLE TORQUE ACTUATED EXPANDABLE CORE CHUCK 6 Claims, 6 Drawing Figs.

[52] 0.5. CI 279/1 DA, 82/44, 242/72, 279/l SG. 279/2 [5l] lnt.Cl B23b 31/40 [50] Field of Search 279/1 DA. 1 SG, 1 T, 2; 82/44; 242/72 [56] References Cited UNITED STATES PATENTS 368,693 1887 Taylor 279/2 Priniary Examiner-Andrew R. Juhasz Assistant Examiner.lames F. Coan Attorneys-Dirk J. Veneman, John S. Munday and Gerald A.

Mathews ABSTRACT: A plurality of elongate chucking members equiangularly disposed about a rotatable central camshaft provide a bidirectionally operable cylindrical core chuck which can be expanded radially by simultaneous outward movement of such members relative to the rotational axis of the camshaft. Each of the chucking members includes two spaced coaxial mounting yokes supported by corresponding circular cams located along the camshaft and offset from the rotational axis thereof. A positioning ring concentric with the chuck axis is provided with radial guide pins which maintain the chucking members in equiangular relation to each other as they are moved outwardly in unison as a result of torque development between the camshaft and any one of the chucking members.

PATENTED nuvso l97| sum 2 OF 2 INVENTOR- GEORGE E. REEDER JR.

BY SOMA M. ROHOSY.

BIDIRECTIONALLY OPERABLE TORQUE ACTUATED EXPANDABLE CORE CHUCK BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved rotatable core chuck or the like adapted to expand radially into symmetrical supporting and driving engagement with an internal bore of a winding core or other rotatably supported member; and more particularly to such a device actuated by torque developed between it and the member carried thereby.

2. Description of the Prior Art Heretofore, many different types of torque-actuated core chucks and related devices have been designed which expand radially into supporting and driving engagement with the cylindrical bore of a winding roll or other member rotatably carried thereby. In most applications, it is important that such devices expand in a symmetrical manner with uniform force in order that the internal bore engaged thereby will be supported in concentric relation to the rotational axis of the chuck. Also, it is important that the expansion of the chuck be effected smoothly and positively in response to the torque reaction between the chuck and the member mounted thereon and that a sufficiently and large uniformly disposed contact area be presented between the chuck and the bore of the supported member to prevent undue localized distortion and abrasion of the latter. Additionally, the mechanical advantage between the torque reaction and the expansion of the chuck must be sufficient to enable relatively low torque to lift a winding core of considerable weight into concentric relation with the chuck axis. Furthermore, the contraction of the chuck in response to termination or reversal of the actuating torque should also be effected smoothly and positively to facilitate the removal of the winding core.

Many previously known torque-actuated expandable chucks of relatively simple construction have failed to satisfy entirely one or more of the foregoing criteria, but nevertheless have been widely employed due to economic considerations. On the other hand, those previously known chuck structures which are capable of meeting all of the aforementioned qualifications have accomplished that goal only through the employment of relatively complicated mechanisms, entailing high costs, elaborate assembly procedures and, in most instances, the sacrifice of ruggedness and reliability.

Still another highly desirable capability of such chucks for many applications is that they be bidirectional, i.e. that a roll or the like can be supported and driven thereby in either direction without modification of the chuck per se. However, in those prior art torque-actuated chucks also incorporating this feature, the attendant complicated and expensive structures employed have given rise to and in most cases have further accentuated the disadvantage recited above.

SUMMARY OF THE INVENTION The present invention provides a simple rugged and reliable chucking device incorporating all of the desirable features summarized above, without involving complicated or expensive components or elaborate assembly procedures. Briefly, the subject chuck comprises a plurality of elongate chucking members equiangularly disposed about a rotatable central camshaft. Each of the chuck members includes spaced coaxial mounting yokes supported by corresponding circular cams located along the camshaft and offset from the rotational axis thereof. A positioning ring generally concentric with the chuck axis is provided with radial guide pins received in the respective chucking members to maintain those members in equiangular relation to each other as they are moved outwardly in unison by their respective cams as a result of torque developed between the camshaft and any one of the chucking members.

Other advantages and features of the improved core chuck provided by the present invention will be apparent from the following detailed description of an illustrative preferred embodiment thereof, reference being made to the accompanying drawings in which like reference characters refer to like elements.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a partially cross sectioned longitudinal view of a core winding chuck according to a preferred embodiment of the present invention, illustrating the chuck in contracted condition within a tubular winding core;

FIG. 2 is a cross-sectional end view of the core chuck depicted in FIG. 1, taken along the line 2-2 ofthat figure;

FIG. 3 corresponds to FIG. 2 and shows the subject chuck in expanded engagement with the illustrated tubular winding core;

FIG. 4 is an end view of the positioning ring assembly of the core chuck;

FIG. 5 is a fragmentary view of an external portion of the chuck depicting the outer end of one of the radial guide pins received in a spherical guide bushing therein; and

FIG. 6 corresponds generally to FIG. 1 but depicts an alternate form of positioning ring assembly located exteriorly of the chucking shoe members.

DESCRIPTION OF THE ILLUSTRATIVE PREFERRED EMBODIMENT As will be seen from the drawings, the illustrative core chuck according to a preferred embodiment of the invention includes a central camshaft member 11 and three chucking members designated generally by numerals 12a, 12b, and 126. For purposes of clarity, the suffixes a, b, and c employed in the drawings may not be recited in all cases in the following description but will be understood to identify various elements of the subject chuck associated with the corresponding chucking members 12a, 12b and 12c. All three such members include substantially identical external shoe members 13 in the form of elongate segments of a longitudinally trisected tube. Along the outer surface of each of such shoe members are provided a plurality of adjacent longitudinal grooves I4 which define parallel central gripping teeth 15. Two yokes 16 extend inwardly from each shoe member and are provided with coaxial cylindrical bearing holes 17 coincident with the partially cylindrical outer surface 18 of the respective shoe member. As shown in FIG. I, the two support yokes of each chucking member are spaced apart by substantially the same distance but the location of the different pairs of yokes is staggered relative to the corresponding shoe members. Also, it should be observed that the bearing holes in the yokes progressively decrease in diameter from the end of the camshaft adjacent hub member 19 thereof.

When the subject chuck is assembled as shown in FIG. I, the bearing holes in the yoke members receive corresponding cylindrical cam lobes 20 located along the camshaft. As illustrated in FIGS. 2 and 3, the two cam lobes associated with each chucking member are coaxial with one another along the corresponding one of three eccentric axes 21, such axes being equiangularly disposed in uniformly spaced relation to the central axis of the camshaft coincident with the axis of elongate bolt 22. A tapered nose piece 23, secured to the end of the camshaft by bolt 222 extending therethrough, is provided with a flat internal surface 24 in adjacent spaced relation to the corresponding ends of the three shoe member. A similar flat surface 25 defined by the enlarge hub member 19 of the camshaft is located adjacent the opposite ends of the shoe members. Consequently, the three chucking members are maintained longitudinally in their respective positions illustrated in FIG. 1. Bolt 22 is threaded into a mating hole 26 in the end of winding machine drive shaft 27 received in bore 28 of hub member 19 and thus serves to mount the chuck device on the drive shaft for coaxial rotation therewith. A key 29 installed in respective keyways 31 and 32 in the shaft and hub member prevents relative rotation between the drive shaft and the camshaft so that rotational torque can be transmitted between those two shafts.

Toward the center of the camshaft, between the adjacent cam lobes 20a and 200, a cylindrical camshaft surface 33 is located concentrically with the axis of rotation of the camshaft. Surrounding this surface is an internal positioning ring 34 having a bore 35 sufficiently large to allow the ring to be slid onto the camshaft past the three eccentric lobes nearest nose piece 23. As is best illustrated in FIG. 4, this ring is provided with three equiangularly spaced radial holes 36 which are threaded to receive guide screws 37. When these guide screws are threaded into place to a depth limited by the abutment of the lower edges of their enlarged cylindrical heads 38 with corresponding flat areas 39 on the periphery of the ring, their innermost end surfaces 41 are in sliding contact with cylindrical camshaft surface 33.

The three cylindrical guide pin heads, in turn, are slidably received in self-aligning guide bushings 42 in the respective chucking members, thereby maintaining those members in equiangular spaced relation to each other while allowing them to move inwardly and outwardly with respect to the camshaft. As shown in FIGS. I and 5, the self-aligning bushings 42 preferably are of the well-known spherical type and are installed in their mating spherical sockets in the chucking members by being inserted edgewise through entrance slots shown at 43 and then rotated to their operative positions.

To assemble the subject chuck, the three chucking members and the positioning ring are oriented relative to one another in the same general positions that they assume in the assembled unit. All four of such members then are slid simultaneously onto the camshaft as each member, in turn, is moved manually relative to the others to allow it to bypass the various cam lobes associated with the other members. The illustrated progressively decreasing diameters of the cam lobes greatly facilitate this assembly operation, which, however, could be performed if all of the cam lobes were of the same diameter but smaller than the inner diameter of the positioning ring. When all three chucking members have been moved into supported engagement with their respective cam lobes, the nose piece is bolted into place and a pointed instrument is inserted through one of the guide bushings and used to orient the positioning ring so that the guide screws can be inserted through the bushings and threaded into that ring. As previously mentioned, the latter operation centers the ring in concentric relation to the rotational axis of the camshaft, whereupon the assembly procedure is completed by installing nose piece 23 and bolting it in place by means of bolt 22.

By reason of the eccentricity of the cam lobes, it will be seen from FIGS. 1 and 2 that the chucking members are fully contracted when their rotational relationship to the camshaft is such that the center of each pair of cam lobes is diametrically opposite the corresponding shoe member with respect to the rotational axis of the camshaft. When the chuck is in this contracted condition, the external surfaces of the shoe members are concentric with the rotational axis of the camshaft. Therefore, a winding core 44, having a tubular bore 45 of slightly greater radius than that of the shoe members, can be slid easily over the contracted chuck as shown in FIGS. I and 2; whereupon it is supported by resting on the gripping tooth portion of the uppermost chuck shoe member 130.

As torque is applied initially to the camshaft by the winding machine, in the direction indicated by arrow 46 in FIG. 3, corresponding rotation of the chucking members is resisted by the winding core frictionally engaged thereby, as well as by any tangential winding tension applied thereto. Accordingly, the camshaft initially rotates relative to the chucking members as shown in FIG. 3, and in so doing causes those members to move outwardly in unison by reason of the eccentricity of the cam lobes. Since all three shoe members are maintained in equiangular relation to each other by the positioning ring structure, the corresponding outer shoe surfaces 18 therefore engage and grip the bore of the winding core to support the latter tightly in concentric relation to the camshaft axis under an expansive force proportional to the torque reaction between the camshaft and the core. It is important to note, however, that the outward movement of the chucking members is not perfectly radial with respect to the rotational axis of the camshaft. In other words, as shown in FIG. 3, the eccentricity of the cam lobes causes the shoe members to be rocked slightly with respect to the core of the winding core, which is engaged by corresponding edge regions of those members. Therefore, the self-aligning support afforded by the spherical guide bushings between the chucking members and guide screws 37 is provided in order to accommodate the relative angular movement between the chucking shoes and the guide screws, which remain at all times in radial relation to the camshaft.

From the foregoing description, it should be evident that the subject core chuck is capable of accommodating winding cores of various internal diameters within a range corresponding to the expansive capability of the shoe members determined by the eccentricity of the camshaft lobes. Furthermore, since all of the elements of the chuck are substantially symmetrical, the chuck expands in the manner just described regardless of the direction of the winding torque imparted to the camshaft by the winding machine, without requiring manual adjustments of rearrangements of components.

The alternate embodiment of the invention illustrated in FIG. 6 of the accompanying drawings is substantially identical to the embodiment shown in FIGS. 1-5 except for the substitution of an external positioning ring 47 for internal positioning ring 34, therefore, reference numerals identifying previously explained elements have been eliminated. The external positioning ring 47 is provided with three equally spaced radial threaded holes 48 which receive positioning screws 49. The respective guide pins 51 defined by the inner ends of those positioning screws are received in corresponding radial holes 52 at the centers of the three external chuck shoe members. These holes are sufficiently larger than the positioning pins to accommodate the relative angular movement previously described in connection with the function of spherical guide bushings 42. Accordingly, it will be apparent that positioning 47 maintains the chuck members in symmetrical relation to one another in substantially the same manner as does internal positioning ring 34. However, by locating the positioning ring exteriorly of the chucking members, the assembly of the chucking unit is substantially simplified. Additionally, the internal bore 53 of the positioning ring can serve to limit the maximum expansion of the chuck, thereby preventing a winding core made of fiber or other relatively weak material from being ruptured by the expansion of the chuck. Since the external positioning ring is easily removable, it can be replaced conveniently with other similar rings of different internal diameters, thus allowing the maximum expansion of the chuck to be limited in accordance with the requirements of the different winding cores. Furthermore, the external ring can be provided with spanner wrench holes 53 or equivalent means, whereby the ring can be rotated manually relative to the camshaft to expand or contract the chucking members.

While the illustrative embodiments of the invention comprise only three chucking members, each supported by two support yokes and two corresponding cam lobes, the invention also contemplates similar devices including greater or lesser numbers of chucking members. Furthermore, the invention is equally applicable to other types of expandable chucks including elongate mandrels supported at both ends, or to winding devices in which similar chucks are installed at opposite ends of the winding core. If the length of such a chuck or mandrel indicates the need therefore, additional supporting yokes and corresponding cam lobes can be provided to further increase the ruggedness and rigidity of the unit.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.

We claim:

1. An expandable torque-actuated chuck comprising:

a. an elongate camshaft rotatable about its longitudinal axis, said camshaft including a plurality of cylindrical cam lobes located at different longitudinal locations along respective cam axes equidistantally disposed around said longitudinal axis if parallel equidistant relation thereto;

b. a plurality of shoe members equiangularly disposed about said camshaft, said shoe members being provided with respective yoke members attaching the same to corresponding ones of said cam lobes for angular movement about the respective cam axes thereof;

. a positioning ring encircling said camshaft and rotatable relative thereto, said positioning ring including a plurality of positioning elements equiangularly disposed about said longitudinal axis of said camshaft in equidistant relation thereto and corresponding in number to the number of said shoe members, said positioning elements include guide elements extending radially from said positioning ring, said guide means being adapted to receive said guide elements in self-aligning relation therewith.

d. guide means operatively connecting each of said shoe members to a corresponding one of said positioningelements to maintain said shoe members in equiangular relation to one another about said longitudinal axis of said camshaft during rotational movement of the latter relative to said shoe member.

2. The invention defined in claim 1 in which said guide elements comprise cylindrical radially disposed pin members, said guide means comprising self-aligning bushings in respective ones of said shoe members adapted to receive respective ones of said pin members.

3. The invention defined by claim 1 in which said positioning ring encircles said shoe members, said ring being provided with a cylindrical internal surface adapted to be engaged by said shoe members to limit maximum expansion of said chuck.

4. The invention defined by claim 3 in which the outer periphery of said positioning ring is provided with surface discontinuities adapted to facilitate manual rotation of said ring relative to said camshaft by means of a wrench member engageable with said surface discontinuities.

5. The invention defined in claim 1 in which said camshaft includes a cylindrical support surface concentric with said longitudinal axis, said positioning ring encircling said cylindrical support surface and being supported thereby for rotational movement relative to said camshaft about the longitudinal axis thereof, and

said positioning elements include cylindrical head portions extending radially outwardly from said ring, said guide means comprising self-aligning bushings in each of said guide shoe members adapted to slidably receive the cylindrical head portions of the corresponding ones of said positioning elements.

6. The invention defined by claim 5 in which said positioning elements are adapted to be threaded into corresponding threaded radial holes in said positioning ring, said cylindrical head portions of said elements being larger than the corresponding threaded holes and serving to limit the depth to which said elements are threaded thereto so that the innermost ends of said elements engage said cylindrical support surface and support said positioning ring for rotation relative to said camshaft about said longitudinal axis thereof. 

1. An expandable torque-actuated chuck comprising: a. an elongate camshaft rotatable about its longitudinal axis, said camshaft including a plurality of cylindrical cam lobes located at different longitudinal locations along respective cam axes equidistantally disposed around said longitudinal axis in parallel equidistant relation thereto; b. a plurality of shoe members equiangularly disposed about said camshaft, said shoe members being provided with respective yoke members attaching the same to corresponding ones of said cam lobes for angular movement about the respective cam axes thereof; c. a positioning ring encircling said camshaft and rotatable relative thereto, said positioning ring including a plurality of positioning elements equiangularly disposed about said longitudinal axis of said camshaft in equidistant relation thereto and corresponding in number to the number of said shoe members, said positioning elements include guide elements extending radially from said positioning ring, said guide means being adapted to receive said guide elements in self-aligning relation therewith. d. guide means operatively connecting each of said shoe members to a corresponding one of said positioning elements to maintain said shoe members in equiangular relation to one another about said longitudinal axis of said camshaft during rotational movement of the latter relative to said shoe member.
 2. The invention defined by claim 1 in which said guide elements comprise cylindrical radially disposed pin members, said guide means comprising self-aligning bushings in respective ones of said shoe members adapted to receive respective ones of said pin members.
 3. The invention defined by claim 1 in which said positioning ring encircles said shoe members, said ring being provided with a cylindrical internal surface adapted to be engaged by said shoe members to limit maximum expansion of said chuck.
 4. The invention defined by claim 3 in which the outer periphery of said positioning ring is provided with surface discontinuities adapted to facIlitate manual rotation of said ring relative to said camshaft by means of a wrench member engageable with said surface discontinuities.
 5. The invention defined in claim 1 in which said camshaft includes a cylindrical support surface concentric with said longitudinal axis, said positioning ring encircling said cylindrical support surface and being supported thereby for rotational movement relative to said camshaft about the longitudinal axis thereof, and said positioning elements include cylindrical head portions extending radially outwardly from said ring, said guide means comprising self-aligning bushings in each of said guide shoe members adapted to slidably receive the cylindrical head portions of the corresponding ones of said positioning elements.
 6. The invention defined by claim 5 in which said positioning elements are adapted to be threaded into corresponding threaded radial holes in said positioning ring, said cylindrical head portions of said elements being larger than the corresponding threaded holes and serving to limit the depth to which said elements are threaded thereto so that the innermost ends of said elements engage said cylindrical support surface and support said positioning ring for rotation relative to said camshaft about said longitudinal axis thereof. 